simplify snapshotting approach

tests/testthat/_snaps/py_require.md

@@ -1,14 +1,19 @@
 # Error requesting newer package version against an older snapshot
 
     Code
-      eval_remote(error = TRUE, {
+      r_session({
         reticulate:::get_or_create_venv(c("numpy<2", "numpy>=2"))
       })
-    Message
+    Output
+      > reticulate:::get_or_create_venv(c("numpy<2", "numpy>=2"))
         × No solution found when resolving `--with` dependencies:
         ╰─▶ Because you require numpy<2 and numpy>=2, we can conclude that your
             requirements are unsatisfiable.
       Error in reticulate:::get_or_create_venv(c("numpy<2", "numpy>=2")) : 
         Python requirements could not be satisfied.
       Call `py_require()` to remove or replace conflicting requirements.
+      Execution halted
+      ------- session end -------
+      success: false
+      exit_code: 1
 

tests/testthat/helper-py-require.R

@@ -2,51 +2,36 @@ test_py_require_reset <- function() {
   .globals$python_requirements <- NULL
 }
 
-
-eval_remote <- function(expr, echo = FALSE, error = TRUE) {
+r_session <- function(expr, echo = TRUE, color = FALSE) {
   expr <- substitute(expr)
-  if(echo) {
-    expr <- call("withAutoprint", expr)
+  if (is.call(expr) && identical(expr[[1]], quote(`{`))) {
+    exprs <- as.list(expr)[-1]
+  } else {
+    exprs <- list(expr)
   }
-  func <- as.function.default(list(expr), envir = asNamespace("reticulate"))
-  func <- rlang::zap_srcref(func)
-
-  out <- tempfile("teststdout", fileext = ".out")
-  err <- tempfile("teststderr", fileext = ".out")
-  on.exit(unlink(c(stdout, stderr)))
-
-  expect_error <- error
-  encountered_error <- FALSE
-  tryCatch(
-    callr::r(
-      func,
-      spinner = FALSE,
-      stdout = out,
-      stderr = err,
-      package = "reticulate",
-      env = c(callr::rcmd_safe_env(), "NO_COLOR" = 1)
-    ),
-
-    error = function(e) {
-
-      encountered_error <<- TRUE
-
-      if(file.exists(out)) writeLines(readLines(out))
-
-      # evaluate::evaluate(), testthat::expect_snapshot(), and friends
-      # do not capture stderr.
-      # https://github.com/r-lib/testthat/issues/1741
-      # https://github.com/r-lib/evaluate/issues/121
-      # to play nice with expect_snapshot(), options are to
-      #  - print via message()
-      #  - print to stdout() using writeLines(foo, stderr())
-      if(file.exists(err)) message(paste0(readLines(err), collapse = "\n"))
+  exprs <- unlist(lapply(exprs, deparse))
+  writeLines(exprs, file <- tempfile(fileext = ".R"))
+
+  result <- suppressWarnings(system2(
+    R.home("bin/R"),
+    c("--quiet", "--no-save", "--no-restore",
+      if (!echo) "--no-echo",
+      "-f", file
+      ),
+    stdout = TRUE, stderr = TRUE,
+    env = c(if (isFALSE(color)) "NO_COLOR=1")
+  ))
+  class(result) <- "r_session_record"
+  result
+}
 
-      if (!expect_error)
-        stop(e)
-    }
-  )
-  if (expect_error && !encountered_error) {
-    stop("expression did not error")
-  }
+print.r_session_record <- function(record, echo = TRUE) {
+  writeLines(record)
+  status <- attr(record, "status", TRUE)
+  cat(sep = "",
+      "------- session end -------\n",
+      "success: ", if (is.null(status)) "true" else "false", "\n",
+      "exit_code: ", status, "\n")
 }
+registerS3method("print", "r_session_record", print.r_session_record,
+                 envir = environment(print))

tests/testthat/test-py_require.R

@@ -4,8 +4,7 @@
 
 test_that("Error requesting newer package version against an older snapshot", {
   local_edition(3)
-  withr::local_envvar(c("NO_COLOR" = 1))
-  expect_snapshot(eval_remote(error = TRUE, {
+  expect_snapshot(r_session({
     reticulate:::get_or_create_venv(c("numpy<2", "numpy>=2"))
   }))
 })